I am looking to fill one PhD position at the University of Munich (LMU) to study sediment transport and weathering across the Madeira floodplain within the ERC-funded project Floodplain Weathering (FloW). The full announcement can be found here. The application deadline is Friday April 25, and I hope to fill the position between July and September this year.
About: Turowski et al., (2025), Earth Surface Dynamics (link)
Chapter four of our work on how channel belts and valleys set their widths is out now. We use a random walk model to make predictions on how channel belts widen. The model is consistent with observations from both experiments and the field, and it is governed by three timescales.
On short timescales, the river moves in just one direction. Then, the channel belt widens linearly at a rate that depends on the rivers “lateral transport capacity”. We introduced the concept of this lateral transport capacity here. On medium timescales, the river moves back and forth across the channel belt. Then, the evolution of channel-belt width can be modelled with an exponential approach to an asymptote. On long timescales the river erodes the margins of the active channel belt only occasionally. The channel belt widens as the squareroot of time.
The model makes predictions on the age of floodplain surfaces, and it fits rare data on floodplain ages well.
Welcome Ao Liu to the Surf@LMU team! Ao is visiting from the China University of Geosciences in Wuhan, and she is funded by a CSC-scholarship. She will study weathering fluxes from shales in Southern China.
I am thrilled to announce that I received funding from the European Research Council (ERC) to study weathering of sediments on floodplains. With this project, I hope to better understand how sediment transport from mountains across lowlands impacts Earth’s carbon cycle. Two PhD positions will likely be advertised throughout next year. Stay tuned for more updates.
Welcome Albert Cabré to the team @LMU! Albert won a DAAD-Prime fellowship to study debris flows in the Atacama desert in collaboration with Andreas Lang (University of Salzburg). Learn more about Albert and his work on his website and google scholar.
About: Erlanger et al., (2024), Nature Geosciences (link)
In our new paper, we use stream water chemistry in two river catchments of the central Apennines to infer the CO2 fluxes from surficial weathering reactions as well as the CO2 degassing from depths.
In the east, where the crust is thick and cold, carbon fluxes from silicate weathering dominate the carbon budget. In contrast, the western catchment is underlain by thin and hot crust. Here, carbon fluxes are dominated by CO2 degassing from the crust and mantle, and these fluxes are up to 50-times higher than the carbon drawdown from silicate weathering.
You can check out a more detailed press-release by the GFZ here.
About: Xu et al., (2024), Environmental Science & Technology (link)
In a new paper spearheaded by Sen Xu from Tianjin University, we investiagate the role of warming for the export of dissolved inorganic carbon (DIC) in two major rivers that drain the eastern Qinghai−Tibetan Plateau.
In the Jinsha River that has 51% of its catchment underlain by continuous permafrost, DIC fluxes increase substantially over the past 40 years. Changes in river discharge play a negligible role for that increase in flux. Instead, the increase in DIC fluxes correlates most strongly with the temperature increase.
The Yalong river that is situated at lower elevation and has only 14% permafrost cover does not show a substantial increase in DIC fluxes. This observation suggest that the presence or absence of permafrost may strongly modulate the sensitivity of inorganic carbon fluxes to global warming.
About: Turowski et al., (2024), Earth Surface Dynamics (link)
What sets the width of river valleys? In a paper published today, we propose a new model for the width of river valleys. It considers valley width as a competition of lateral channel motion and the uplift and erosion of valley walls. Here is the equation:
W is valley width
qL is the lateral sediment transport capacity
qH is the lateral input of sediment from hillslopes
U is the uplift rate
W0 is the channel belt width
WC is the channel width
A dimensionless “mobility-uplift number, MU” expresses that competition where:
The model implies that valley width varies between two extremes: At a minimum, valleys are as wide as the channel. Such narrow valleys occur where rivers drain rapidly uplifting landscapes. At a maximum, valleys encompass wide channel belts. These two extremes are connected by a logarithmic function of the mobility-uplift number.
Despite its conceptual simplicity, the model compares surprisingly well to several datasets including experiments and a large compilation of valley widths in the Himalaya.
This model explains valley width in a landscape that has reached steady state. How do valleys evolve over time and what sets the maximum width of valleys? We are working on these questions in an upcoming publication.
About: Bufe et al., (2024), Science (link)
In this new paper, we analysed weathering data from different mountain ranges. We found that silicates, carbonates and sulfides had different non-linear erosion sensitivities. The behaviors are very similar in all study areas. As a result, all datasets show that CO2 drawdown from rock-weathering is at a maximum at moderate erosion rates of ~0.07 mm/yr.
You can read press-releases here with more info.
Welcome to the team, Kaja Schultz. Kaja will research chemical weathering in the Black Forest and Bhemian Massif.
